The Final Frontier: The Science of Star Trek

As the new movie warps into theaters this week, we ask physicist Lawrence Krauss, author of The Physics of Star Trek, how the sci-fi franchise keeps it real, and also how it bends--or breaks--a few laws of nature

Ever since the starship Enterprise first whisked across television screens in 1966, Star Trek has inspired audiences with its portrayal of a future, spacefaring humanity boldly going where no one has gone before.

Creator Gene Roddenberry's vision went on to spark five other TV series and now 11 movies, as a new film hits multiplexes this week. This prequel, simply titled StarTrek and directed by J. J. Abrams—the force behind TV's Lost and Fringe, among other projects—chronicles the early years of Captain Kirk and some of his Enterprise shipmates, including Spock, McCoy and Uhura.

To get a sense of how much actual science has made its way into the science fiction universe of Star Trek,ScientificAmerican.com spoke to Lawrence Krauss, author of The Physics of Star Trek, the first edition of which appeared on bookshelves in 1995. Krauss is a theoretical physicist at Arizona State University's School of Earth & Space Exploration and the director of the university's Origins Initiative, a project that explores big questions such as human consciousness and the beginning of the universe. Krauss is also the author of several other books and co-author of the Scientific American articles: "The End of Cosmology?," "A Cosmic Conundrum," and "Should Science Speak to Faith?".

We asked Krauss about the plausibility of crossovers from the Trek universe, including warp speed, humanoid aliens such as Klingons and, of course, whether anyone will be "beamed up" by Scotty or otherwise, anytime soon.

[An edited transcript of the conversation follows.]

You penned the original edition of The Physics of Star Trek about 15 years ago. What is an example of something in science that has changed dramatically since then?
When I first wrote the book, we thought most stars could have planets, but we had no idea of the frequency or of the diversity of ways that exoplanets could form. [Since the discovery in 1995 of the first planet orbiting a normal star other than the sun, more than 300 exoplanets have been found.—Editor's note]

So we know these planets are out there. What about actually getting to them? Let's talk warp drive.
I don't think we're any closer to warp drive—it was and is still a wild idea. Applying what we know about general relativity, the idea of faster-than-light travel is possible in principle. You can expand space behind you and contract it in front of you and therefore quickly go from one place to another across the galaxy. But the amount of energy required is just unfathomable. So while getting to exoplanets fast is still far-fetched, getting to them slow is no more far-fetched than it was before. I think that's the way we're going to do it eventually—we're not going to be building warp drives anytime in the near future.

As we "seek out new life and new civilizations," per the opening credits of the original series and The Next Generation, do you think we'll actually find anything living beyond Earth?
Not only have we learned that life is far more robust here on Earth and living in environments that we once thought impossible, but there are life-forms that can survive dormant for millions of years in rather extreme circumstances. The idea of panspermia, in which microbial life could travel across interplanetary distances and maybe even interstellar distances to seed other worlds, is not so crazy anymore. We have also learned there are environments even right here in our solar system that are promising for life. There's water on Mars, and it was probably once warm; Jupiter's moon Europa likely has a liquid ocean. For exoplanets not in the [Earth-like] Goldilocks zone around their stars, maybe they have an environment sustainable for [non–Earth-like] life. Perhaps there is life out there that is silicon-based rather than carbon-based like our own.

What about aliens that resemble us, like the Vulcans, Klingons and Romulans, along with virtually every other race on Star Trek?
While the likelihood that there isn't life elsewhere is extremely small, the likelihood that extraterrestrial life resembles life on Earth is probably not great either, in my opinion.

As for dealing with potentially hostile aliens, what exactly are phasers?
Phasers are like lasers, really—they are directed-energy weapons.

Could they exist someday?
I just got one on my iPhone. You can go online and download a phaser app because of the new movie. I thought I'd better have it.

But the problem with a real phaser is that it would be pretty hard to generate the energy to heat something or someone up to a billion degrees to vaporize them. You would get some recoil, too.

What about space ordinance—that is, photon torpedoes?
Well, I could never understand the name, because photon torpedoes are antimatter weapons. You get the biggest bang for your buck that way—you never get more energy than you do when you annihilate matter with antimatter. That's why the warp drive is matter–antimatter-powered, as well. Of course, it's hard to create antimatter, much less carry it around. It takes a tremendous amount of energy to produce antimatter. If we used the antimatter-making device at Fermilab just outside Chicago, the energy cost would be many thousands of times the gross national product of the U.S. to produce enough antimatter to light up a lightbulb. As for storing antimatter, you need huge magnetic fields to keep it away from touching container walls made of matter. Given the infrastructure required to keep antimatter around, it might be more effective ounce-for-ounce to just carry around hydrogen bombs.

What about when the space weaponry is aimed at you?
The shields in Star Trek work by bending space like gravity, so objects get carried away with space as it gets bent around the ship. Sounds great, of course, but as I say in my book, the sun, which is a million times the mass of Earth, bends light around it by less than a thousandth of a degree. So it's very hard to imagine the gravitational energy that would be needed to swerve something 90 degrees. I think the only kind of shields that are feasible are those that would destroy the incoming object before it hits you, rather than diverting it.

On to, "Beam me up." How plausible are transporters?
As I discovered pretty quickly, I would not make a transporter the way the Star Trek writers do. First you decompose somebody into a matter stream, although taking a person apart at the atomic level would require heating them up to a few billion degrees. Then you turn them into energy. However, the energy equivalent of an average human being is something like a 1,000-megaton nuclear weapon, so that's not environmentally friendly either.

So I would do what I do when I surf the Internet—I'd move the bits. I'd scan you and try to get all the information, the bits, which make you a human being. But that's a hell of a lot of information. From Earth, you'd have to stack 100-gigabyte hard drives a third of the way to the center of the Milky Way or so to hold it all. And at current information transfer rates, it would take longer than the age of the universe to transmit that much data. But the key obstacle is still the Heisenberg uncertainty principle, which says I can't scan you and measure you at the atomic level to make an exact replica of you, much less actually put you together in a remote place with atomic resolution. [As Krauss points out in his book, the Star Trek writers get around this physical showstopper by outfitting transporters with "Heisenberg compensators".—Editor's note]

What about quantum teleportation?
That's one of the things that has happened since the book was first written. Quantum teleportation does for a single atom essentially what the transporter is supposed to do for people. The phenomenon is possible with single atomic states only because of the weirdness of quantum mechanics. If people were quantum mechanical, we could run into walls and every now and then we could go through them. That hasn't happened for anyone I know, but you can try and experiment if you want. So we'll be able to do this for single atoms or molecules but not for Hungarian goulash or people.

How might particle accelerators such as the Large Hadron Collider (LHC) near Geneva, Switzerland, and its ilk push the envelope on physics as presently understood and perhaps get us closer to Star Trek?
We will no doubt learn more from those machines about the fundamental nature of space and time and matter, and that will obviously help us understand issues that ultimately would be related to everything from extra dimensions to creating exotic energy configurations that we might need for warp drive. There's the remote possibility that at the LHC we might actually discover extra dimensions in space beyond the four that we've measured. These dimensions may even be large enough to fit aliens or other universes in—and from a Star Trek perspective, nothing could be better, right?

What are some potential insights related to Star Trek involving dark energy?Dark energy produces a gravitationally repulsive force throughout empty space. In fact, dark energy is causing regions of the universe now to move away from us faster than the speed of light, or at "warp speed" in the Star Trek sense. Dark energy is just the kind of thing you need to put behind a spacecraft to make space expand behind it exponentially and make the ship travel faster than light. Unfortunately, as I've written, the impact of this expansion is that the rest of the universe will disappear before our very eyes.

Time travel: Do you think it's possible?
The time travel episodes are about my favorite ones in Star Trek. They often come down to some kind of weird paradox. If time travel is possible then we have to somehow understand how we can build a physical universe in which you can kill your grandmother before you were born.

An example I gave in my book is a wormhole where one end of the hole is moving through space very fast and the other is static. Say one end of the wormhole is moving in a big circle five light-years around, and it takes nearly five years for it to move in that circle. If you're sitting on the fast-moving end of the wormhole, because of special relativity your clock is slowed down, so the whole trip might take just a week. If you then went through the wormhole, you'd come out five years minus a week behind in time. Suppose the wormhole is located two light-years away and you get back at near light-speed, then you can arrive back three years before you left.

If you could create a traversable wormhole, then you could create a time machine, there's no doubt about it. But the question is: Can you create a traversable wormhole? And that all depends on having weird negative energy configurations. We simply don't know if that's possible. It's not ruled out, but I wouldn't bet on it. It's an open question for modern physics that people like me continue to work on every day.

The biggest question: Of all the TV series, which is your favorite?The Next Generation is the best series overall, though I think some of the best individual episodes may have been in the first, classic series, if you suspend disbelief and take into account that the special effects were much worse.

If you had to pick just one, who is your favorite Trek character?
I always liked the science guys. So in some sense Spock was interesting in the first series, and I kind of like Data [the android from The Next Generation]. Data is probably my favorite character.